We deploy a pretty brutal but absolutely necessary firewall. While it does a great job at identifying zero day exploits in a heuristic manner, sometimes innocent behaviour can still get flagged.
Here are some of the reasons you may get a firewall blocked screen:
Sometimes innocent behaviour can fall through the cracks. In the past, the firewall has been so strict even innocent javascript we built for navigation can get caught up. We have identified almost every legitimate action possible. This also includes our internal creator page builder. In the likelyhood you were caught in this, simply respond to the contact form on the block page and we will cross check this and get in contact with you.